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相关论文: Variability of sub-mJy radio sources

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From 43GHz VLBA observations of the pair of radio sources 1928+738 and 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at millimeter wavelengths. For a pair of sources with 5…

天体物理学 · 物理学 2007-05-23 J. C. Guirado , J. M. Marcaide , M. A. Perez-Torres , E. Ros

We present Very Long Baseline Interferometry (VLBI) observations 217 days after the gamma-ray burst of 2003 March 29. These observations provide further measurements of the size and position of GRB 030329 that are used to constrain the…

天体物理学 · 物理学 2009-11-10 G. B. Taylor , E. Momjian , Y. Pihlstrom , T. Ghosh , C. Salter

The results of GRANAT/SIGMA hard X-ray observations of GRS 1758-258 in 1990-1998 are presented. The source lies at ~5\arcdeg from the Galactic Center and was within the SIGMA field of view during the GRANAT surveys of this region. The total…

We report the first detections of the repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using the 4$-$8 GHz receiver of the Robert C. Byrd Green Bank Telescope with the Breakthrough Listen digital…

Studying the spatial distribution of extragalactic source populations is vital in understanding the matter distribution in the Universe. It also enables understanding the cosmological evolution of dark matter density fields and the…

宇宙学与河外天体物理 · 物理学 2022-10-12 Aishrila Mazumder , Arnab Chakraborty , Abhirup Datta

We made simultaneous single-dish and very long baseline interferometer (VLBI) observations of a narrow-line Seyfert 1 galaxy (NLS1) 1H 0323+342, showing gamma-ray activity revealed by Fermi/LAT observations. We found significant variation…

星系天体物理 · 物理学 2015-06-18 Kiyoaki Wajima , Kenta Fujisawa , Masaaki Hayashida , Naoki Isobe , Takafumi Ishida , Yoshinori Yonekura

Deep radio observations at 5 and 8 GHz are presented of a complete sample of 11 radio galaxies with redshifts 0.85 < z < 1.5, selected from the 6C sample of Eales. The radio data, taken using the VLA in A, B and C array configurations,…

天体物理学 · 物理学 2015-06-24 P. N. Best , S. A. Eales , S. Rawlings , H. J. A. R"ottgering , M. S. Longair

In this study, we compare the radio, optical and environmental properties of GRGs with those of a control sample of smaller RGs we found in the three LOw-Frequency ARray (LOFAR) deep fields, namely the Bootes, ELAIS-N1, Lockman Hole, for a…

星系天体物理 · 物理学 2024-03-14 M. Simonte , H. Andernach , M. Brueggen , G. K. Miley , P. Barthel

We report the time variability of the late-time radio emission in a Type-I superluminous supernova (SLSN), PTF10hgi, at z = 0.0987. The Karl G. Jansky Very Large Array 3 GHz observations at 8.6 and 10 years after the explosion both detected…

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

天体物理学 · 物理学 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel

We present 1.4 and 5 GHz observations taken with the Very Large Array (VLA), and observations at 250 GHz obtained with the Max-Planck millimeter bolometer (MAMBO) at the IRAM 30~m telescope, of ten optically selected Quasi-stellar Objects…

This paper presents the results of a detailed X-ray spectral analysis of a sample of 123 X-ray sources (46 being type-1 AGN and 28 type-2 AGN) detected with XMM-Newton in the Lockman Hole field. Using a single power law model our sources'…

天体物理学 · 物理学 2009-11-11 S. Mateos , X. Barcons , F. J. Carrera , M. T. Ceballos , G. Hasinger , I. Lehmann , A. C. Fabian , A. Streblyanska

Using the Urumqi 25m radio telescope, sources from the first three-month Fermi-LAT detected AGN catalog with declination >0 were observed in 2009 at 4.8 GHz. The radio flux density appears to correlate with the gamma-ray intensity.…

宇宙学与河外天体物理 · 物理学 2015-05-30 Xiang Liu , Hua-Gang Song , Jun Liu , Zhen Ding , Nicola Marchili , Thomas P. Krichbaum , Lars Fuhrmann , Anton Zensus , Tao An

We have formed a complete sample of 26 low redshift (z < 0.3) giant radio galaxies (GRGs) from the WENSS survey, selected at flux densities above 1 Jy at 325 MHz. We present 10.5-GHz observations with the 100-m Effelsberg telescope of 18…

天体物理学 · 物理学 2009-10-31 A. P. Schoenmakers , K. -H. Mack , A. G. de Bruyn , H. J. A. Rottgering , U. Klein , H. van der Laan

Intrinsic variability was searched for in arrival times of six gamma-ray bursts (GRBs) at high energies -- between 30 MeV and 2 GeV -- detected by the Fermi satellite's Large Area Telescope (LAT). The GRBs were selected from the Fermi LAT…

高能天体物理现象 · 物理学 2024-07-31 E. Casey Aldrich , Robert J. Nemiroff

This is the first of two papers describing the observations and cataloguing of deep 3-GHz observations of the Lockman Hole North using the Karl G. Jansky Very Large Array. The aim of this paper is to investigate, through the use of…

星系天体物理 · 物理学 2016-07-27 Tessa Vernstrom , Douglas Scott , Jasper Wall , Jim Condon , Bill Cotton , Rick Perley

We present the results from two radio integrations at 8.4 GHz using the VLA. One of the fields, at 13h,+43d (SA13 field), has an rms noise level of 1.49 microJy and is the deepest radio image yet made. Thirty-four sources in a complete…

天体物理学 · 物理学 2009-11-07 E. B. Fomalont , K. I. Kellermann , R. B. Partridge , R. A. Windhorst , E. A. Richards

We have studied Very Long Baseline Array (VLBA) polarimetric observations of 8 sources including quasars and BL Lacs at 12, 15, 22, 24 and 43 GHz and high frequency rotation measure ($RM$) maps are presented. We find typical values for the…

高能天体物理现象 · 物理学 2015-06-12 J. C. Algaba

We present results from daily radio continuum observations of the Bootes field as part of the Pi GHz Sky Survey (PiGSS). These results are part of a systematic and unbiased campaign to characterize variable and transient sources in the…

To fully exploit the scientific potential of the Fermi mission, we initiated the F-GAMMA program. Between 2007 and 2015 it was the prime provider of complementary multi-frequency monitoring in the radio regime. We quantify the radio…